Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Radio tomographic imaging of the Arctic ionised atmosphere by the International Ionospheric Tomography Community (IITC)  (Tomographic imaging of the Arctic ionosphere)

Outline
The ionised atmosphere in the polar regions is a highly structured plasma containing irregularities in electron density over a wide range of horizontal scale-sizes. The structure is influenced largely by the solar wind as it sweeps past the Earth, with the coupling of the interplanetary magnetic field in the solar wind to the magnetospheric field leading to a series of complex processes that result in a dynamic and structured ionospheric plasma. During times of disturbed geomagnetic activity, enhancements and gradients in the plasma density can cause severe disruption to transionospheric radio signals, affecting communications and navigation systems. The basic physics and chemistry of ionisation production and loss in the polar regions are understood reasonably well, including effects of large-scale plasma transport and precipitation of charged particles into the atmosphere. However, the actual structure present in any given situation depends on the relative contributions of the various processes and the balance remains an open question that needs to be addressed by experimental observations. To date measurements of the ionospheric density in the remote polar regions have been scarce. Radio tomography is a relatively new technique for imaging the ionospheric plasma over extended height-versus-latitude planes. In essence, radio transmissions from polar-orbiting satellites are monitored at a chain of receivers aligned in longitude but separated in latitude. Measurements of the line integral of the electron density along satellite-to-receiver ray paths, the so called total electron content, are inverted in a reconstruction algorithm to yield an image of the spatial distribution of the density over the region of interest. Routine monitoring of transmissions from satellites over an extended period of time leads to coverage of the ionosphere at all Universal Times, seasons, geomagnetic and solar conditions. The technique gives wide spatial coverage from a limited number of ground stations and so is ideal for remote inaccessible polar regions. Observations from a single chain can of necessity reveal only a localised, limited view of the density distribution. However, observations from several chains separated in longitude have the potential to provide the spatial distribution of plasma over an extended geographic region. The International Polar Year opens the unique opportunity for increased collaborative tomographic observations of the distribution of the polar ionospheric plasma over large geographic regions and long time intervals, to study signatures of space weather in the Arctic ionosphere.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The topology of the geomagnetic field with field lines converging at high latitudes makes the polar ionosphere a unique vantage point for studying the geophysical weather processes that couple the solar wind to the terrestrial environment. These processes occur over very large volumes of space in the distant magnetosphere, and of necessity can only be occasionally sampled by spacecraft at few locations. When the processes are mapped down the geomagnetic field lines their signatures are brought into closer proximity. Observations of the ionospheric footprints offer spatial and temporal coverage of the signatures, and enable monitoring of the impact of space weather on the terrestrial environment on a routine basis.

What international collaboration is involved in this project?
Collaboration between international research groups with tomographic chains deployed in different sectors at northern high latitudes, with co-ordination under the International Ionospheric Tomography Community (IITC): University of Wales Aberystwyth, Wales Sodankylä Geophysical Observatory, University of Oulu, Finland NorthWest Research Associates, USA University of Alaska Fairbanks, USA Applied Research Laboratories, University of Texas, USA Polar Geophysical Institute of Russian Academy of Sciences, Russia M.Lomonosov Moscow State University, Russia

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Geographic locations of tomography chains operated by the groups: University of Wales Aberystwyth (UWA): Svalbard to northern mainland Norway Sodankylä Geophysical Observatory (SGO): Sweden and Finland NorthWest Research Associates (NWRA) and the University of Alaska Fairbanks: Alaska Applied Research Laboratories(ARL), University of Texas Austin and NWRA: Greenland Polar Geophysical Institute (PGI) and Moscow State University (MSU): Svalbard, auroral and subauroral to midlatitude west Russia

Approximate timeframe(s) for proposed field activities:
Arctic: 03/07 - 03/09            
Antarctic: n/a

Significant facilities will be required for this project:
Most of the tomography receiving systems are presently deployed in the Arctic and run essentially unattended. Provision required is: Continued availability of satellite radio sources. Continued housing of the receiving systems with network connections. Routine maintenance visits to the sites. The latter two are currently funded from various national sources open to the participants, which may continue; in the case of UWA a PPARC rolling grant.

Will the project leave a legacy of infrastructure?
Removal of receiving equipment from the remote sites at the end of the project is included in the plans. The legacy will be scientific measurements and results.

How is it envisaged that the required logistic support will be secured?
National agency
Own support
Other sources of support

Logistics are presently organised by the individual research groups, with the housing for equipment at institutions/organisations in the Arctic regions. Financial support is provided by national research funding bodies.

Has the project been "endorsed" at a national or international level?
No. Tomographic chains are "endorsed" for current operation, with funding forthcoming for deployment from national funding agencies. Endorsement not yet sought for the time period of IPY observations. The Russian tomographic chain is included in the list of national scientific facilities currently supported by the Russian Ministry of Sciences and Education (formerly - Russian Ministry of Sciences and Technology).

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
Expansion
The project is not a component of a formal larger initiative. However, it is complementary to other proposed IPY ideas with, in particular, cooperation and collaborative links with UAMPY (Upper Atmosphere Monitoring for Polar Year 2007-2008): Idea 367.

How will the project be organised and managed?
Organisation and management of the individual chains will be by the individual institutions, as is presently the case. Co-ordination between the different groups will occur under the umbrella of the International Ionospheric Tomography Community (IITC). The IITC is an outgrowth of a workshop that was conducted under the Polar Aeronomy and Radio Science (PARS) program and was sponsored by the US Office of Naval Research via a grant to the University of Alaska and sub-grant to NWRA.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Activities to promote spaceweather science and the physics of the upper polar atmosphere, may include: - interaction with local schools - teaching of undergraduate and postgraduate students - communication in the local media

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
It is desirable for total electron content measurements and tomographic reconstructions for all chains to be stored centrally within national data centres in common format. This would require some funding above present levels.

How is it proposed to fund the project?
Grant applications to be submitted to national funding agencies, including: UK: PPARC research council USA: Airforce Research Laboratory, National Science Foundation Finland: Academy of Finland Russia: International Science and Technology Center (ISTC), Ministry of Science and Education

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Dr S Eleri Pryse
Institute of Mathematical and Physical Sciences
Penglais
Aberystwyth
SY23 3BZ
UK

Tel: +44 1970 622801
Mobile:
Fax: +44 1970 622826
Email:

Other project members and their affiliation

Other Information